Swift开发：GCDAsyncUdpSocket 通信之UDP广播

       功能需求：

                 发送广播，搜索设备

【在wifi下无法接收广播，原因: 路由器阻止广播】

1 使用GCDAsyncUdpSocket 实现广播

   下载地址：包含tcp和udp，共4个文件 http://download.csdn.net/detail/taoerit/9809540

2 Swift Code:

//

//  ViewController.swift

//  3-SwiftSocket-udp

//

//  Created by 黄涛 on 17/4/10.

//  Copyright © 2017年 huangtao. All rights reserved.

//

import UIKit

class ViewController:UIViewController,GCDAsyncUdpSocketDelegate {

    @IBOutletweakvar btnStart:UIButton!

    

    @IBOutletweakvar lbRecvMsg:UITextView!

    

     var mainQueue =dispatch_get_main_queue()

    var udp:GCDAsyncUdpSocket!;

    

    let localPort:UInt16 =54321;

    

    let boardcasePort:UInt16 =1001;

    

    overridefunc viewDidLoad() {

        super.viewDidLoad()

        

        btnStart.addTarget(self, action:"btnStartClickFun",
forControlEvents:UIControlEvents.TouchUpInside)

        

        udp =GCDAsyncUdpSocket(delegate:self, delegateQueue:dispatch_get_main_queue());

        do

        {

            tryudp.enableBroadcast(true)

            tryudp.bindToPort(localPort,
interface:udpError);

            tryudp.beginReceiving();

        }

        catch{

            

            print("catch:\(udpError)")

        }

    }

    

    

    var udpError:String?;

    

    func btnStartClickFun(){

        //开始广播

        udp.sendData("#SYSTEM\n".dataUsingEncoding(NSUTF8StringEncoding),
toHost: "255.255.255.255", port:boardcasePort, withTimeout: -1, tag:0);

        

    }

    

    func udpSocket(sock:GCDAsyncUdpSocket!, didReceiveData data:NSData!,
fromAddress address:NSData!, withFilterContext filterContext:AnyObject!) {

        

        let recv:NSString =NSString(data: data, encoding:NSUTF8StringEncoding)!;

        // 2 主界面ui显示数据

        dispatch_async(mainQueue, {

            let showStr:NSMutableString =NSMutableString()

            showStr.appendString(recvasString)

            showStr.appendString("\n")

            self.lbRecvMsg.text = showStrasString;

            

        })

        

    }

    

    func udpSocket(sock:GCDAsyncUdpSocket!, didNotConnect error:NSError!)
{

        print("连接失败：\(error)")

    }

    func udpSocket(sock:GCDAsyncUdpSocket!, didSendDataWithTag tag:Int)
{

        print("已经发送数据:\(tag)")

    }

    

    

    func udpSocketDidClose(sock:GCDAsyncUdpSocket!, withError error:NSError!)
{

        print("断开连接 error:\(error)")

    }

    

    func udpSocket(sock:GCDAsyncUdpSocket!, didConnectToAddress address:NSData!)
{

        print("开始连接")

    }

    

    overridefunc didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

}

3 效果图